David DiSalvo is the author of "Brain Changer: How Harnessing Your Brain’s Power to Adapt Can Change Your Life" and the best-selling "What Makes Your Brain Happy and Why You Should Do the Opposite", which has been published in 10 languages. His work has appeared in Scientific American Mind, Forbes, Time, Psychology Today, The Wall Street Journal, Slate, Salon, Esquire, Mental Floss and other publications, and he’s the writer behind the widely read science and technology blogs “Neuropsyched” at Forbes and “Neuronarrative” at Psychology Today. He can be found on Twitter @neuronarrative and at his website, daviddisalvo.org. Contact him at: disalvowrites [at] gmail.com.

Vitamins: Good for You, Bad for You, or What?

This week research came out in the Journal of the American Medical Association (JAMA) suggesting that taking a daily multivitamin may reduce the incidence of cancer in older men (specifically, the study concluded: “daily multivitamin supplementation modestly but significantly reduced the risk of total cancer”).

On the face of it, this seems like good news for the vitamin industry and has probably already boosted sales. But, we really need to examine these findings within the larger context of what research has indicated about vitamin supplementation in recent years.

A 2008 study of 15,000 participants showed that taking the vitamins E and C had no effect on cancer rates.

Another study of 35,000 men, conducted just a few months before that one, showed that taking vitamin E and selenium had no impact on cancer rates, and the researchers actually stopped the study early because there appeared to be a slight increase in cancer and diabetes among study participants.

Then, in November 2008, another study of nearly 15,000 participants indicated that taking vitamins C or E had no impact on the incidence of heart attack, stroke, congestive heart failure or angina. Researchers tracked results over eight years.

A year prior to that, in a study also published in JAMA, researchers concluded that taking vitamin B12 supplements are not effective in preventing strokes, heart attacks or death in people with a history of vascular disease. In this case, the study was a review that covered 12 studies with 16,598 participants who had pre-existing illness.

Then in 2011, a whopper of a study was published in the Archives of Internal Medicine indicating that multivitamins, folic acid, iron, copper, magnesium, zinc, and vitamin B6 supplements all increased an older woman’s risk of dying from any cause. This was an observational study of roughly 16,000 women, so it was not able to establish a cause and effect relationship between taking the supplements and death, but the correlation was significant.

It’s worth noting, however, that in the same study, calcium supplementation was associated with a reduced risk of death.

To round things out, it’s also helpful to take a look at this September 2012 piece in Consumer Reports that describes 10 dangers of vitamins and supplements.

So, yes, the most recent research shows a modest reduced risk of total cancers among older men taking a multivitamin, but the overall research track record of vitamin supplementation isn’t as encouraging.

The best policy is to do your homework before taking a vitamin or supplement and don’t start taking one just because it seems like the healthy thing to do. As the research shows, it may very well not be.

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Thank you for highlighting the study highlighting the value of multivitamins. More than half of all Americans take dietary supplements safely and effectively as part of a healthy lifestyle. The Natural Products Association has addressed the shortcomings of many of the studies cited in this article, including by Consumer Reports. Read what NPA had to say at www.NPAinfo.org/NPAResponds.

David — I have my own skepticism here, but I think it’s important to note those previous studies were observational studies, which are much less trustworthy. This was a randomized controlled trial. I still think it is an important question whether we just throw out those other studies because we got this one positive result.

Well, since this post was quite obviously meant to be a survey of the past few years’ worth of vitamin research, I’m not sure how it does “major injustice to the subject.” If your point is that a far longer piece could be written on the finer points of vitamin research over time, I don’t disagree, but that wasn’t the intention of this piece.

I don’t know if this is true about vitamins, but I know I lost my grandmother, my Uncles, my mother, and my oldest sister to cancer. Yes! I don’t know if they took vitamins before they got cancer or after.But I still think that Vitamins are good sources of balance with all the drugs Dr’s put You on for illnesses,with all the additives in foods, with like all things in our air that we breathe and etc. So I think I’ll continue to take my chances with my vitamins.

This is the biggest crock of shit I have ever read. You can go ahead and delete this comment after you read it, but how much nutritional experience do you even have? Also if that picture is current you clearly have no idea how to even take care of yourself. Vitamins are essential in the function of the human body all those studies neglect to include the persons diet as well as exercise during that time period. simply taking a b-12 or vitamin C wont cut it. Vitamins don’t work like medication you don’t take one kind for one sickness. It boggles me how its your belief that that is how things need to treated. Scaring people from common good health knowledge and facts; to support the big businesses that are over medicating your american public (i’m from Canada) is hilarious to see on a website that i though was Credible. You would have been better off not writing anything at all then to add another incompetent anti vitamin story.

If you personally feel that a good quality vitamin is good for you, then it is, today it is important I believe. To take care of your body, and many of our foods today can lack in nutrients and vitamins. But once again, I personally believe that taking one vitamin a day can not hurt you, unless your physician says otherwise. Remember please take a good brand name quality vitamin and not something just of the shelve, keep updated and educated on your health. Live long and prosper…Peace